Sea Of Change

Desalination plants are expensive and environmentally risky, but emerging technologies and economies of scale can make them a sustainable solution.

by BusinessToday.InMay 13, 20198 minutes

Situated off India's south west coast, Kavaratti Island, the capital of Union Territory Lakshadweep, is surrounded by pristine beaches and calm waters. But finding potable water was a challenge for the islanders. High saline content made groundwater unfit for drinking, and bringing large quantities of water from the mainland was not an option. People tried several measures: open wells, rainwater harvesting, and more, but nothing worked.

In 2005, Chennai based National Institute of Ocean Technology (NIOT) set up a desalination plant with a capacity of 1,00,000 litres potable water a day. Desalination is a large scale exercise of removing salt from seawater. The NIOT plant provides continuous supply of drinking water to more than 10,000 people in Kavaratti, bringing down incidences of waterborne diseases.

Cases of dysentery have dropped from 200 to 10 a year, and instances of diarrhoea and water borne hepatitis reduced significantly. The success of the desalination plant prompted NIOT to set up low temperature thermal desalination (LTTD) plants in Lakshadweep's Agatti and Minicoy Islands too. "We are putting up such plants in six more islands," says Purnima Jalihal, Head (Energy and Fresh Water Group), NIOT. "We are also setting up the world's first self powered desalination plant in Lakshadweep."

Cut to Chennai, a city notorious for water scarcity. In early 2000s, the city faced acute water shortage as its four reservoirs went dry, and residents were forced to pay hefty